Biotechnological Significance of Biodegradation of Bioplastics
Authors: Subhasree Raya,b*, Vipin Chandra Kaliaa,b
aMicrobial Biotechnology and Genomics, CSIR - Institute of Genomics and Integrative Biology (IGIB), Delhi University Campus, Mall Road, Delhi-110007.
bAcademy of Scientific & Innovative Research (AcSIR), 2, Rafi Marg, Anusandhan Bhawan, New Delhi- 110001.


Introduction

Bioplastics, such as Polyhydroxyalkanaotes (PHAs) are produced by many microbes to store excess carbon as food reserve, under adverse conditions. There are a host of microbes which have the ability to metabolize PHA with the help of the enzyme called as Depolymerase.

Biodegradation of PHAs

The PHA biodegradation involves extracellular and intracellular depolymerizing enzymes.

Bacterial PHA depolymerases

Intracellular PHA depolymerases have been reported in Alcaligenes, Comamonas, Pseudomonas, Rhodospirillum, Ralstonia, Stenotrophomonas, Streptomyces and Rhodococcus.



Fungal PHA depolymerases

Fungi such as Ascomycetes, Basidiomycetes, Deuteromycetes, Mastigomycetes, Myxomycetes, Zygomycetes, Penicillium and Aspergillus degrade PHB and its co-polymers by extracellular PHB depolymerase.

Biological significance of PHA depolymerases

The bioproducts generated by PHA degradation can be used as biofuels, fuel additives, probiotics, and as pharmaceuticals. The metabolic intermediates such as Hydroxyalkanoic acids (HA) can be used as biofuels and as additives to enhance fuel efficiency. HA have the unique characteristic of being used as drug delivery agents. 3-(HAs) can also be exploited for producing antibiotics - macrolids. PHA degradation products within the gastrointestinal tract can act as biocontrol agents. One of the most interesting feature of HAs and their oligomers is their use as memory enhancers and as bioindicators (Pollution sensors).

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About Author / Additional Info:
Researchers in Microbial Biotechnology and Genomics at CSIR-IGIB, Delhi.